The solvent used for removing grease stain is

Correct answer: Turpentine

Explanation: Grease is largely non-polar, so it is best removed by a non-polar organic solvent (“like dissolves like”). Turpentine (a mixture of terpenes) is non-polar and dissolves oils and grease effectively.

• Turpentine — Correct. Non-polar solvent; dissolves grease/oils well.
• Ammonia solution — Aqueous and basic; may help by emulsifying some soils but is not a true solvent for grease.
• Ethanol — Polar protic; limited ability to dissolve heavy grease compared to non-polar solvents.
• Borax solution — Works as an alkaline builder/emulsifier in cleaning, not as a grease solvent.